Plots the sensitivity of ILUD for A.
spilu_iludplot(A) data = spilu_iludplot(A) data = spilu_iludplot(A,N) [data,hAlpha] = spilu_iludplot(...) [data,hAlpha,hDrop] = spilu_iludplot(...)
a n-by-n sparse matrix
a 1-by-1 matrix of doubles, integer value, the number of points in the plot (default N = 100)
a N-by-6 matrix of doubles, the values of the parameters
a graphics handle, the alpha plot
a graphics handle, the drop plot
For one particular matrix, plot norm(A-L*U)/norm(A) and nnz(L)+nnz(U), depending on alpha and drop for the ILUD method.
The columns of the array data are:
data(:,1) : the values of alpha
data(:,2) : the values of norm(A-L*U)/norm(A) with respect to alpha
data(:,3) : the values of nnz(L)+nnz(U) with respect to alpha
data(:,4) : the values of drop
data(:,5) : the values of norm(A-L*U)/norm(A) with respect to drop
data(:,6) : the values of nnz(L)+nnz(U) with respect to drop
If the decomposition does not work for one value of the parameter, then norm(A-L*U)/norm(A) and nnz(L)+nnz(U) are set to Infinity.
A = [ 34. 4. -10. 0. -3. 4. 24. -8. 0. 0. -10. -8. 36. 0. 0. 0. 0. 0. 1. 0. -3. 0. 0. 0. 6. ]; A = sparse(A); spilu_iludplot(A); // See on a 225-by-225 sparse matrix path = spilu_getpath ( ); filename = fullfile(path,"tests","matrices","pde225.mtx"); A=mmread(filename); [data,hLfil,hDrop] = spilu_iludplot(A); | ![]() | ![]() |